As methods of producing gel negative electrodes for conventional alkaline batteries, a method wherein a gelling agent is first dispersed uniformly in an electrolyte to obtain a gel electrolyte and then the gel electrolyte is mixed with a zinc powder by agitation (the wet mixing method), and a method wherein a zinc powder is first mixed with a gelling agent to obtain a dry powder mixture and then the dry mixture is mixed with an electrolyte by agitation (the dry mixing method) are known (for example, Japanese Laid-open Patent Application No. Hei 10-208754 and Japanese Laid-open Patent Application No. 2000-30695).
In the above-mentioned dry mixing method, a V-shaped agitator and a pot mill, for example, are used; however, there is a problem that the zinc powder agglutinates, and the zinc powder and the gelling agent also agglutinate during agitation and mixing, whereby a uniform gel negative electrode cannot be obtained. Furthermore, there is a problem that the discharge characteristic of an alkaline battery using the gel negative electrode produced in this way has a wide range of variation.
On the other hand, in the above-mentioned wet mixing method, there is a problem that a long time is necessary for uniform dispersion and mixing when preparing the gel electrolyte, and the gelling agent is liable to become lumpy during mixing. These problems were unable to be solved sufficiently even when any types of agitators were used.
Accordingly, an object of the present invention is to overcome the above-mentioned problems and provide a method of producing a gel negative electrode for an alkaline battery, the method being able to prepare a gel negative electrode in which a zinc powder, a gelling agent and an electrolyte are dispersed uniformly. Furthermore, another object of the present invention is to provide an alkaline battery excellent in discharge characteristic by using the gel negative electrode obtained by the above-mentioned production method.